苯酚的褐煤吸附过程及影响因素分析

以污染物苯酚为研究对象,褐煤作为吸附剂,通过批量实验研究了褐煤对废水中苯酚的吸附特性,考察了褐煤粒径、褐煤投加量、反应温度、反应p H、反应时间对吸附作用的影响,并对吸附过程进行了分析。采用Lagergren动力学方程和拟二级吸附动力学方程分析苯酚吸附过程,结果表明,褐煤对苯酚的吸附动力学曲线更符合拟二级吸附动力学方程,反应初始速率随着苯酚初始浓度的升高而增大,但随着煤粉粒径的增大而减小。颗粒内扩散模型对苯酚的吸附动力学曲线分析结果表明:苯酚在褐煤上的吸附首先经历了速率较快的膜扩散控制阶段,进而经历了吸附较缓慢的颗粒内扩散控制阶段,最后到达吸附平衡,褐煤对苯酚的吸附过程主要受到颗粒内扩散控制。

Adsorption of Phenol in Water by Lignite and Impact Factor Analysis

In this paper,phenol was selected as the study target and lignite was taken as the adsorbent.A series of orthogonal experiments were designed to evaluate the adsorption characteristics of phenol from phenol simulated wastewater by lignite.In the meantime,the effects of lignite particle sizes,lignite dosage,temperature and pH of mimic phenol solutions on phenol removal were investigated.The process of adsorption of phenol from wastewater onto lignite was also studied.Lagergren kinetic and pseudosecond-order kinetic models were used to analyze the phenol adsorption process and the data was found to follow the pseudosecond-order kinetics well.The initial adsorption rates derived from the models increased with the concentration of phenol but decreased with the size of lignite.The process mechanism was found to be complex,consisting of first quick surface adsorption and then slow pore diffusion.Analysis of sorption data using an intra-particle diffusion plot confirmed the particle diffusion as the ratelimiting step for the adsorption of phenol onto lignite.